JPS63107288A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To sufficiently remove cross talk components by constituting a delay line for a comb line filter of charge transfer devices, and supplying a chrominance subcarrier phase-locked to a horizontal synchronizing signal included in a reproduction luminance signal to the delay line as a clock. CONSTITUTION:The charge transfer devices constitute the delay line 22 for the comb line filter 21 to remove the cross talk components accompanied by the reproduction of signals. A synchronizing separation means 9 isolating the horizontal synchronizing signal from the reproduction luminance signal Y, chrominance subcarrier generation means 33 and 35 and a means 30 synchronizing the chrominance subcarrier with the horizontal synchronizing signal are provided. The chrominance subcarrier phase-locked to the horizontal synchronizing signal is supplied as a clock to the delay line 22. Since a voltage controlled oscillator 33 is phase-locked to the horizontal synchronizing signal, the frequency of its output, that is, the frequency of the chrominance subcarrier outputted from a 1/4 frequency divider 35, fluctuates like a reproduction horizontal frequency. Besides to that, the delay time of the delay line 22 fluctuates in the same way that the time base of the reproduction signal fluctuates.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device having a comb-shaped filter for removing crosstalk.

[Summary of the invention]

The present invention provides a magnetic recording and reproducing device that uses a comb filter to remove crosstalk components from adjacent tracks, in which an IH or 2H delay line in the comb filter is configured with a charge transfer element, and the delay line Horizontal synchronization of the reproduced luminance signal (color image phase-synchronized to No. 1 + l
By supplying the I transmission wave as a clock, crosstalk components can be sufficiently removed even if the time axis of the reproduced signal changes.

[Conventional technology]

First, the Soviet video tape recorder (hereinafter abbreviated as VTI) will be explained with reference to FIGS. 2 and 3.

An example of the structure of ILF raw silk for a conventional VTR is shown in FIG.

In FIG. 2, T is a videotape, and on the inclined track there is an FM luminance fR number YFM whose frequency is varied by a luminance signal Y, and an FM luminance fR number YFM whose frequency is converted to a lower frequency side than this signal YFM. The narrowed-down color signal CQ is recorded using multiple frequencies. Then, the FM luminance signal YFM and the 1st forward color f3 CQ recorded in a given trunk and those in the adjacent track are interleaved in frequency with each other.
Their frequency or phase is changed.

The reproduction 1'2F signal from the reproduction magnetic head (11) is supplied to a high-pass filter (3) and a low-pass filter (4) via a reproduction amplifier (2), and is then converted into an FM luminance signal Y and a low-pass conversion carrier. The color signal CQ (IIQ transmission frequency fp) is separated into a color signal CQ (IIQ transmission frequency fp).These signals YFM and CQ contain crosstalk components from the adjacent 1f+- rack, and the processing thereof will be described later.

The FM luminance signal YFITI is demodulated by a demodulator (5) to become a luminance signal Y, which is delivered to an output terminal OUT via a low-pass filter (6), a subtracter (7), and an adder (8).

The low-pass converted carrier color signal CQ is supplied to the first frequency converter (11) of the color signal processing circuit (10).

In the color signal processing circuit (10), the output (frequency E sc±rQ) of the second frequency converter (12) is supplied to the first frequency converter (11), and the low frequency conversion carrier color signal is supplied to the first frequency converter (11). C2 is returned to the original carrier color signal C (frequency f sc ). This carrier color signal C has a center frequency f sc
is supplied to an adder (20) via a bandpass filter (13). This addition W”l+<2o> has a low-pass filter (
A luminance signal Y is supplied from 6).

Addition 'I! The output of I (20) is supplied to the adder a (81) via a comb filter (details will be described later) (21) and a bandpass filter (14) and is output to the output terminal OUT, and is also supplied to the burst sampling circuit (15). ), and a burst flag formed from the horizontal synchronization signal of the reproduced luminance signal Y extracts a color burst signal transmitted together with the carrier color signal C. The phase is compared with the output of the crystal oscillator (17) in the phase comparator (16).
) is fed through a low-pass filter (18) to a voltage controlled oscillator (VCO) (19). VCO (19)
(7) The output of the frequency f2 is sent to the second frequency converter (
12), where it is mixed with the output of the crystal oscillator (17), converted to a frequency of E sc±rQ, and the first
frequency converter (11). This forms an automatic phase control (APC) loop, in which the carrier color signal C is phase synchronized with the output of the crystal oscillator (17), and the VT
Even if there is a time axis fluctuation during reproduction of R, the phase continuity of the color subcarrier of the reproduced color signal is maintained, and the colors of the reproduced image are correctly reproduced.

The delay line (22) of the comb filter (21) is, for example, CO
It is composed of a charge transfer element such as D, and the frequency is f.
The output of the SC crystal oscillator (17) is supplied as a clock, and the delay time of one horizontal period (IH) is obtained over the entire frequency band of the video signal? Being ignored.

Composite video signal Y+ formed in adder (20)
C is fed to this comb filter (21) and the subtraction 'a
(23) Nioi c, delay line (22) ni, k li I
The signal Y-C of the preceding line, which has undergone the a extension of H, is subtracted from the signal Y+C of the current line to obtain the carrier color signal 2C of twice the level. Signal C is taken out. As is well known, this comb filter (21) has frequency characteristics as shown in FIG.

As described above, during recording, the FM luminance signal YFM and the low frequency conversion carrier color signal CQ are recorded so as to be frequency interleaved with each other between two adjacent tracks on the magnetic tape T. Therefore, the reproduced luminance signal Y and the reproduced carrier color signal C are in a frequency interleaved relationship, and the reproduced luminance signal Y of the main track and the associated crosstalk component Yct of the luminance signal from the adjacent track are interleaved. , and also between the reproduced carrier color signal C of the main track and the accompanying crosstalk component Cct of the carrier color signal from the adjacent track. Therefore, the frequency spectra of the luminance signal Y and the crosstalk component Oct of the color signal match, and the frequency spectra of the 1-speed color signal C and the crosstalk component YcL of the luminance signal match.

As a result, in the comb filter (2]), the crosstalk component Cct of the 1st forward color signal is removed together with the luminance signal Y, and the crosstalk component Yct of the luminance signal is output together with the 1st narrowing color signal C. .

In this way, a carrier color signal C without crosstalk components is extracted via the bandpass filter (14).

On the other hand, the output of the comb filter (21) is supplied to the band rejection filter (24) to remove the carrier color signal C, and the small amplitude crosstalk component Yct of the luminance signal is transmitted to the limiter (24).
5), the signal is amplitude-separated and taken out, and is supplied to subtraction 1:f L71 via an attenuator (26) for level adjustment, where it is canceled out by the crosstalk component Yet associated with the luminance signal Y. As a result, a luminance signal Y without crosstalk components is extracted from the subtracter (7).

Note that a technique for removing each crosstalk component of a luminance signal and a carrier color signal using a single comb-shaped filter as described above is disclosed in Japanese Patent Application No. 59-244096 (Japanese Patent Application Laid-open No. 61-123296) filed by the present applicant. ) has already been proposed.

[Problem that the invention seeks to solve]

By the way, in the conventional VTR shown in FIG. 2, the output of the reference crystal oscillator (17) for APC is
Since it is supplied as a clock to the H delay line (22), the delay time of the delay line (22) is accurately fixed to lH.

However, if there is jitter in the VTR's playback signal, its time axis changes, the horizontal period of the playback signal becomes a different value for each line, and the position of each spectral component of the playback signal on the frequency axis also changes. .

For this reason, there is a problem in that the crosstalk component to be removed also deviates from the valley of the transmission characteristic of the comb filter (21), and is not removed sufficiently.

In view of the above, an object of the present invention is to sufficiently remove crosstalk components from adjacent trunks even if the time axis of the reproduced signal changes. The present invention provides a magnetic recording/reproducing device.

(Means for solving the problem) The present invention interleaves the frequency of crosstalk components from adjacent tracks for each of the luminance signal and the carrier color signal with respect to the main No. 13 component from the original 1-rack. A magnetic tape processed and recorded as shown in FIG. In the magnetic recording and reproducing apparatus which uses a comb-shaped filter (21A>) to remove the signal, the delay line (22) is constituted by a charge transfer element, and synchronization component n1 means for separating the horizontal synchronization signal from the reproduced luminance signal Y. (9), means (33) for generating color subcarriers, and (
35) and means (30) for phase-synchronizing the color subcarrier with the horizontal synchronization signal, and supplying the color subcarrier phase-synchronized to the horizontal JIJI signal to the delay line (22) as a clock. It is a recording/playback device.

[Effect]

According to the configuration, even if the time axis of the reproduced signal changes,
Crosstalk components from adjacent tracks are sufficiently removed.

〔Example〕

An embodiment of the magnetic recording/reproducing apparatus according to the present invention will be described below with reference to FIG.

FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, parts corresponding to those in FIG. 2 are designated by the same reference numerals and redundant explanation will be omitted.

In FIG. 1, (30) is a PLL for AFC, and its phase comparator circuit (31) is supplied with a signal obtained by a synchronization separation circuit (9) from a reproduced luminance signal Y derived from a subtracter (7). A horizontal synchronization signal is supplied. In addition, the phase comparator circuit (31) is connected to the 1/910 frequency divider (32).
The output of VCO (33) is supplied, and the phase comparator circuit (3
The output of 1) is passed through a low-pass filter (34) to the VCO
Be supplied to (33). This reduces the frequency to 4 f
The output of the SC VCO (33) is phase-locked to the horizontal synchronization signal of the reproduced luminance signal Y.

The output of this VCO (33) is supplied to a 1/4 frequency divider (35), and the output of the frequency divider (35), whose frequency has been lowered to rsc, is the output of the crystal oscillator (see Figure 2). Alternatively, the second frequency converter (12) of the color signal processing circuit (IOA)
and the phase comparator circuit (16), and is also supplied as a clock to the IH delay line (22) of the comb filter (21A'). The rest of the structure is the same as that shown in FIG.

If the time axis of the reproduced signal fluctuates due to uneven running of the magnetic tape T, uneven rotation of the reproducing head 11), etc., the interval of the horizontal synchronizing signal obtained from the synchronization separation circuit (9), that is, the horizontal period, will also be near the IH. fluctuate. As mentioned above, the VCO
Since (33) is phase-locked to the horizontal synchronization signal, its output, and therefore the period of the color subcarrier output from the 1/4 frequency divider (35), fluctuates in the same way as the reproduction horizontal period.
The delay time of the COD delay 1jl (22) using the output of the frequency divider (35) as a clock also varies at the same rate as the time axis variation of the reproduced signal. For this reason, a comb filter (2
The position of the valley of the transmission characteristic in 1A) on the frequency axis changes in accordance with the time axis fluctuation of the reproduced signal, following the position of each spectrum, and the crosstalk component to be removed is sufficiently removed.

Although a normal comb filter was used in the above-described embodiment, the present invention can also be applied to a feedback type comb filter as described in Japanese Patent Application Laid-Open No. 61-123296.

Further, in the above embodiment, an NTSC system VTR was used, but in the case of a PAL system, the delay time of the CCD delay line (22) may be changed from IH to 2H.

〔Effect of the invention〕

As described in detail above, according to the present invention, the delay line of the comb-shaped filter is configured with a single load transfer element, and the horizontal synchronization of the reproduced luminance signal (color subcarrier phase-synchronized with the r? signal) is applied to this delay line. Since the clock signal is supplied as a clock, a magnetic recording/reproducing device can be obtained that can sufficiently remove crosstalk components from adjacent tracks even when the time axis of the reproduced signal changes.

Brief Description of Page 1 FIG. 1 is a block diagram showing the configuration of an embodiment of the magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a block diagram showing an example of the configuration of a conventional magnetic recording/reproducing apparatus. The figure is a characteristic curve diagram for explaining the present invention.

(9) is a synchronous separation circuit, (21A) is a comb filter, (
22) is the IH delay line, (30) is the AFC pr, L
, , (33) is a voltage controlled oscillator, and (35) is a 1/4 frequency divider.

Claims (1)

[Scope of Claims] A magnetic tape in which each of a luminance signal and a carrier color signal is processed and recorded so that crosstalk components from adjacent tracks are frequency interleaved with respect to main signal components from the respective original tracks. In a magnetic recording and reproducing apparatus, the crosstalk components accompanying each of the reproduced luminance signal and the reproduced carrier color signal are removed using a comb-shaped filter including a 1 or 2 horizontal period delay line. is configured by a charge transfer element, and includes synchronization separation means for separating a horizontal synchronization signal from the reproduced luminance signal, means for generating a color subcarrier, and means for phase-synchronizing the color subcarrier with the horizontal synchronization signal. A magnetic recording and reproducing apparatus, characterized in that the color subcarrier phase-synchronized with the horizontal synchronization signal is supplied to the delay line as a clock.